Grains processed to relatively fine particle sizes have been known since prior to recorded history. Apparatus used for processing of various grains to fine particles or flours have advanced from stone implements to present day roller mills, pin mills and the like, the common denominator of many prior systems being the impact nature of prior grinding processes. In such impact processing, relatively high damage starch values are commonplace with certain grains. Whole grains, in particular, while recommended in the diet, are processed in most prior art situations with a resulting flour characterized by the presence of large pieces of bran, thus yielding a flour not suitable for the expectations of modern baking practices. Whole grain flours processed according to prior art methodology further lack an acceptable, uniform appearance and are subject to becoming rancid under normal storage conditions as well as subject to infestation by insects and the like that feed on flours. Grains have previously been processed to particle sizes on the order often microns, such particle sizes being typically referred to as ultra-fine flours. U.S. Pat. No. 6,083,547 discloses the use of a hammer mill to produce a flour of an average particle size of approximately 36 microns followed by processing in a pin mill to achieve a finer particle size. Flour having an increased shelf life is disclosed in U.S. Pat. No. 5,433,966, the flour being treated in a heated carrier gas to dry the flour to a moisture content of less than seven weight percent. U.S. Pat. No. 5,352,473 also discloses heat treatment of flour to reduce the moisture content of the resulting flour. Production of a whole grain oat flour is disclosed in U.S. Pat. No. 5,523,109. Flours prepared from a variety of natural sources are disclosed in U.S. Pat. No. 5,789,012 inter alia. Wheat is processed to produce white flour by removal of at least portions of the bran layer of the wheat grain from the endosperm and germ portions thereof followed by grinding in a roller mill to produce a flour of a relatively fine state as is disclosed in U.S. Pat. Nos. 5,114,079 and 5,192,028. U.S. Pat. Nos. 5,194,287; 5,089,282 and 5,104,671 disclose pearling of wheat to remove outer layers of bran and germ followed by grinding in a roller mill. In U.S. Pat. No. 5,063,078, flours are disclosed having high soluble dietary fiber content, the process including grinding in a pin mill to a particle size in the range of 30 to 60 microns. U.S. Pat. No. 5,137,133 discloses “micronized” grains cooked and heated to form particles of relatively large sizes but which are referred to as having been micronized.
The prior art has not contemplated the processing of grains whether whole or partial grains by subjection of such material to resonance disintegration processes according to preferred embodiments of the invention, processing according to the invention reducing the grains to “flours” of consistent particle sizes and uniform appearance without impacts and thus without crushing with the usual high damage starch values as occurs with impact grinding. Flours produced according to the invention are of enhanced quality and are resistant to rancidity yet retain acceptable baking performance whether or not rehydrated. Whole grain flours produced according to preferred methods are improved when compared to typical whole grain flours produced by impact milling processes. Processing of whole or partial grains according to preferred embodiments of the invention therefore constitute substantial advances in the art.